def constant(f):
    def fset(self, value):
        raise SyntaxError
    def fget(self):
        return f()
    return property(fget, fset)

class _Const(object):
    @constant
    def ERROROUS_WORD():
        return 0
    @constant
    def VALID_WORD():
        return 1
    @constant
    def EMPTY_SPACE():
        return 2
    @constant
    def SINGLE_LETTER():
        return 3
    @constant 
    def HORIZONTAL():
        return "horizontal"
    @constant
    def VERTICAL():
        return "vertical"
    @constant
    def INVALID_SEQUENCE():
        return "invalid_sequence"
